St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1887-01-30


blocks 4x5xl2 inches in size. These are laid
on gravel and sand foundation and consti-
tute an excellent pavement for purely resi-
dence streets. They do not stand up well un-
der heavy traffic, and l cannot see that they
possess any advantage over the sheet asphalt,
except that no flour is required to lay them,
which may make them cheaper in cases where
the area of pavement to be laid
is small. Ordinarily they cost about
the same as sheet asphalt. They are
used In Washington for streets of light traffic
and for alleys. Many streets in Baltimore
some bearing quite heavy traffic, and other
cities, are paved with asphalt blocks. This
pavement is more easily repaired. 1t is itfi-
cult to repair q defective area with new
blocks and preserve the uniformity of the
roadwa. surface. Kerrs patent wood pave
ment, a sample of which was laid
ON ROBERT STREET
in 1885, is Enthusiastically an excellent pave
ment when properly constructed. Many
miles of this pavement have been laid in Lon
don, Paris and other European cities. Wood
makes the most pleasant, and when new per-
haps the best wearing surface known. but its
rapid deterioration is a serious objection,
and a decayed wood "a vement is worse
than none. The durability and healthful-
ness Of a wooden pavement are increased
by subjecting the blocks TO some one of the
many preseryatlve processes. In Europe it
is customary to provide for the maintenance
OF wooden pavements by the contractors for
long periods Of time, usually twenty years.
The Kerr pavement, for these reasons, is an
expensive luxury.
/ understand that the wooden blocks laid
on Robert street we're not thoroughly creo-
soted; that they were merely dipped in bath
of creosote Oil. Each of the various wood
preservative processes, whether mercury,
zine, calcium, iron or copper salts, creosote
or dead OIL be the preservative used, requires
COmDletG
wood fibre and its replacement by the
preserving liquid, or else such comb nation
between the sap and the preservation as will
destroy the deleterious qualities OF the for
mer. This can only be effected by forcing
the liquid into the wood by hydraulic or
gravity pressure or by boiling the wood in
the oil and then suddenly changing the bath
to cold Oil, coLdensing the gases in the wood
fibres and forcing the cold Oil into the partial
vacuum thus formed. Dipping wood into
such a bath only tends to inclose the sap
more completely and certainly does not re-
tard decay.
The Nicholson wood pavoments laid in
Washington during the Shepherd regime,
were supposed to have been constructed with
creosoted blocks, but the preserving process
was evidently not thoroughly carried out,
for the pavements went to pieces with
almost entirely replaced with asphalt and dis
tilIate. This experiment cost the District of
Columbia something over S4,000,0O0.
The Robert street pavement cost $2.40 per
square yard, and is not guaranteed. Had the
blocks been thoroughly creoseted the cost
would probably have been greater, as this is
an expensive process. The cost of mainten-
ance of a wood pavement in such a climate as
that of Washington is greater than that of
any other first-clasS pavement because of its
rapid deterioration. its durability in this
latitude has yet to be determined. With such
Sc toI1r
that every step in the was of preparation and
construction should be subjected to rigid and
thorough inspection. The policy of throwing
the responsibility of maintenance upon the
contractors is wise; it insures the laying of a
good pavement. In Washington the law re-
quires all new work to be guaranteed for FIVE
years. The various brick pavements are OF
the same general class as the asphalt block.
AS q rule, tIe5 lack durability, and their
rapid deterioration more than counterb.l-
ances the saving in first cost. Some years
ago bricks made of fire clay were tried in st.
Louis with considerable success. They
showed only moderate wear after three
years exposure to heavy traffic on one Of
the principal streets. a fund was
raised by the citizens to defray the
cost of further experiments, and it
was hoped that durable and cheap pave
ment had at last been found. Though re-
peatcd trials were made, bricks could not be
obtained of the same quality as those first
prod need, and the committee were reluctantly
compelled to report that while the possibility
OF manufacturing good paving bricks out of
fire clay had been proven by the endurance of
the original pavement, the subseq uent UNI
successful efforts showed that the practical
difficulties were toe great to be overcome
The best and most durable pavemeuts Of this
class are those laid with the West Virginia
brick. Which is the best pavement? This is
to general question to answer. Ifcomfort
be the only consideration, sought
aud the property owners are will
ing to defray the cost of renewing
the pavement at comparatively frequent in
teryals, the Kerr or some other form of good
wood pavement is probably the best. If dura-
bility alone be considered, use granite blocks.
If smooth, comfortable and desirable pave
meng be wanted, one that Will last from ten
to twenty years. lay asphalt or coal tar dis
tiate. If economy in first cost be the ruling
consideration, cedar blocks will stand at the
head of the list. Each of these payements
has
ITS SPECIAL ADVANTAGES.
Ali are good pavements when properly laid
and maintained
The life of a pavement varies with the
character and extent of the traffic which it
supports. In general, the wearing sur
face should not require renewal
at more frequent intervals than
every ten years, and under favorable
even longer. In this country our experience
with modern concrete pavtments has been
mainly confined to the past twelve or fifteen
years, and statements as to the endurance of
such paVementS are more or less problemati-
cal. Until accurate and extensive traffic OBJ
servations shall be made, and unit estab-
lished to which all observations can be re-
duced, comparisons of different pavements
will continue to be more or less inaccurate
and misleading. emitting other consdera-
tfons, pavement which supports double
the traffic Of a second pavement should
only last half as long, and should cost twice
as much for maintenance. If the total traffic
be observed for several days and q mean
taken, the daily traffic can be expressed in
tons per foot of roadway (width). Assuming
some fixed number of tons per foot of road
way as Il unit, we have means of reducing
all observations to the same standard
and comparing different pavements with
each other, as well as the same
pavement under different conditions.
The following are the Washington prices for
the present fiscal year:
Granite block; the district supplies the
material, but the total cost is about So. 10 per
square yard.
Standard sheet asphalt e parts hydraulic
base) 1925 per square yard. A bid at this
price could not be accepted because of a
clause In the appropriation bill limiting the
cost of concrete pavements to 81 per square
yard.
Sheet ashpalt (modified bid for four parts
hydraulic base, containing 25 per cent. of
Portland cement), So per square yard.
Asphalt block, 81 per square yard. The
price was placed at this figure in consequence
of the limiting clause of the appropriation
bill. The block pavement cannot proftably
be laid at this price.
Coal tar distillate, S1.97 per square yard.
These prices are lower than those which
obtain in any other city of the United States.
Over two and quarter million of dollars
have been expended in paving the streets and
avenues of Washington during the past eight
years, an annual average of nearly $3.50, 00O
As result, Washington is now one of the
best paved cities in the world.